Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive behavior, so the bar is lower; the description adds that a one-time token is required (auth constraint) and that format=srt|vtt|txt returns only that text rather than the full JSON payload. It does not describe what a not-yet-complete job returns, which would be the remaining useful detail.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tight sentences with the async-job scope front-loaded and the format behavior last. Slight density cost from unexplained abbreviations ('SRT/VTT') and the 'Free:' prefix, but nothing is wasted.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description carries the burden of naming return values, and it does (transcript, segments, SRT/VTT text). It stops short of describing the in-progress state (status values, whether to poll again) or token expiry, which would make a polling tool fully self-explanatory.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3; the description goes beyond it by clarifying that the token is single-issue and that non-default format values short-circuit the response to plain text only. That is genuine added meaning about how format changes behavior, not just restating the enum.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific resource and scope: status, progress, and, once finished, transcript/segments/subtitle output of an async job, with jobId tied explicitly to speech_job_submit. An agent can immediately tell this is the polling/result-retrieval tool rather than a submit or quote tool.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives the prerequisite context (must have jobId plus the jobToken shown once at submit) and explains the format selection path. It does not state exclusions such as when to re-submit instead of polling, but the lifecycle positioning is clear enough to act on.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.